SEEIAL TEMPERATUEES. 23 



The water of the western part of the line as a whole being warmer than 

 the eastern part, the intrusion of a large body of cold water between 

 Station 4721 and Station 4717, between 50 and 200 fathoms, is a marked 

 feature of the northern end of the line Galapagos to Manga Reva. 



Only two serial temperatures were taken at Stations 4740 and 4742 on 

 the line Manga Reva to Acapulco (PL 12). To the eastward on the line, 

 Galapagos to Manga Reva we took a number of serial temperatures, passing 

 from the colder water of the Humboldt current to the warmer waters south 

 towards Manga Reva. The temperatures at 200 fathoms are nearly 

 identical. North, a great change in temperature takes place between 25 

 and 200 fathoms, where there is a difference of 24'. South the belt of warm 

 water extends 100 fathoms, a great change occurring between 100 and 200 

 fathoms, a drop of 16 \ The serial temperatures taken at the southern and 

 northern edges of the cold current on the line Manga Reva to Acapulco 

 agreed well with those taken in the same current to the east. 



Station 4725, which is in the same latitude as 4740, shows a difference 

 (colder) of 4' at the surface, of 5" at 50 fathoms, of 2' at 100 fathoms, and 

 of 0°.3 at 200 fathoms. 



Station 4714 which is a little to the south of the western Station 4742, 

 shows a difference (colder) of 2" at the surface, 3".4 at 50 fathoms, IIM at 

 100 fathoms, 1^4 at 200 fathoms, while at 300 and 400 fathoms the western 

 station is colder, 1 .2 at 300 fathoms, and 1 .6 at 400 fathoms. At 800 

 the temperature is 39 .4 at both stations. 



It may not be out of place to correlate the temperature results ol)tained 

 south of the Panamic region with those (obtained in the Panamic district 

 by the "Albatross" in 18'Jl.' 



A transverse section of the Mexican current from Mariato Point to 

 Cocos Island shows the existence of a cold current running north parallel to 

 the coast : the northern extension of a branch of the Humboldt current. 

 This is pushed to the east by the Mexican branch of the California current 

 and also by the easterly equatorial set. The latter is deflected to the west- 

 ward and becomes a part of the westerly equatorial current flowing well 

 north of the eastern set which flows by the Galapagos in the oceanic basin 

 between them and Acapulco as far as Lat. 12" N., while in the oceanic 

 valley separating Galera Point and the Galapagos there is a wide current 

 of cold water flowing north towards the Bay of Panama. 



> Bull. M. C. Z. XXIII, No. 1, p. 12, 1902. 



